If the delay of the first trains results in the connection time dropping below the minimum connection time then you can treat the connection as missed. And in that case you can take the next train. But for small delays it is common for trains to wait. For example in Interlaken Ost departing trains will wait up to 3 minutes for delayed trains.
Once I was travelling to Belalp, and our IC to Brig was delayed by 3 minutes. When we arrived at the bus stops in fron of the station all the busses had “+3” on their departure boards. They know that the IC was late, and all the buses waited…
Its like a relay race, and you are the baton. So for example take Lugano: If the RE80 arrives before the IC there has left the conductor will hold the train there long enough so that everyone can make the transfer. Of course if the RE80 is delayed longer then the IC will not wait, but then you can of course just take the next train (even an EC in this case…)